This proposal is directed towards the concern that before image reconstruction techniques can reasonably be applied to routine clinical procedures in nuclear medicine, further investigations are required to accomplish two major goals. The first is the optimization of the numerical calculations associated with transverse section tomography. The second is to develop methods which require only minor modifications to conventional imaging instrumentation. The specific aims include the evaluation of various methods for absorption correction, the development of a compatible data link between the Nuclear Medicine Laboratory and the Computing Center and the development of low cost patient positioning devices for imaging various human organs.